Here is a list of all files with brief descriptions:

doc
doxygen
include
algorithm
arrangement.hpp	Planar subdivision induced by a set of one-dimensional shapes
bitmatrix.hpp	One bit per cell over a fixed rectangular window of the integer grid
closestpair.hpp	Closest pair of points by divide and conquer
convexhull.hpp	Convex hull algorithms built from Pangolin point predicates
graph.hpp	Simple undirected graph with hashable vertices
intersections.hpp	Segment intersection and crossing algorithms
intervaltree.hpp	Mutable one-dimensional interval tree over projected bounded shapes
mindisk.hpp	Smallest enclosing disk algorithms
polyominoes.hpp	Enumeration of polyominoes as Pangolin polygons
redbluesweep.hpp	Bichromatic (red-blue) boundary contact by one combined plane sweep
shapetree.hpp	Static 2D shape tree over any bounded shape (one exposing bbox())
sortpoints.hpp	Angular sorting of points around a center
triangulation.hpp	Mutable triangulation of a point set or simple polygon
xysweep.hpp	Bounding-box sweep over pairs of segments
core
bigint.hpp	Arbitrary precision signed integers, optimized for small values
forward.hpp	Forward declarations for core numeric and geometry types
handle.hpp	Strongly typed index handles shared by the topological data structures
hash.hpp	Hash support for Pangolin value types
numeric.hpp	Numeric concepts and helpers shared by exact geometry operations
rational.hpp	Exact rational number type used when geometric results need fractions
transformation.hpp	Public declaration of pgl::Transformation, an affine transformation
implementation
atxy.hpp	Coordinate-evaluation helpers for linear primitives
booleans.hpp	Regularized boolean operations on closed polygonal regions
boundarycontains.hpp	Implementations of the 'boundaryContains' predicate
bounding.hpp	Bounding-box and rectangle-boundary operations
closest.hpp	Witnesses for squaredDistance: which elements realize it, and where
contains.hpp	Implementations of the 'contains' predicate
crosses.hpp	Implementations of the 'crosses' predicate
distance.hpp	Distance and Hausdorff-style measurements between shapes
distancel1.hpp	Manhattan (L1) distance between shapes
distancelinf.hpp	Chebyshev (LInf) distance between shapes
duality.hpp	Projective duality and polar-transform helpers
interiorcontains.hpp	Implementations of the 'interiorContains' predicate
interiorsintersect.hpp	Implementations of the 'interiorsIntersect' predicate
intersection.hpp	Implementations of the 'intersection' predicate
intersects.hpp	Implementations of the 'intersects' predicate
io.hpp	Stream output helpers for Pangolin value types
lattice.hpp	Enumeration of the integer grid points a shape contains
measures.hpp	Geometric measurements and canonical representative-point helpers
minkowski.hpp	Minkowski sums of two shapes, and the operator+ that spells them
minkowskierosion.hpp	Minkowski erosions: the set of translations of one shape that keep it inside another
minkowskisum.hpp	Minkowski sums whose result is not a single convex shape: one region when the substantive case is connected and regular, several only when thin or slit geometry can genuinely separate it, and one polygon for the receiver whose monotonicity rules holes out
orientation.hpp	Exact low-level orientation and incircle predicates
predicates.hpp	Method definitions for the shapes
predicates_helpers.hpp	Small dispatch traits and geometry helpers reused by the implementations
samepointset.hpp	Exact equality of the point sets represented by arbitrary shapes
separates.hpp	Implementations of the 'separates' predicate
transformations.hpp	Arithmetic transformations and explicit conversions between primitives
visibilitygraph.hpp	Visibility graphs by triangular expansion
shape
convex.hpp
disk.hpp	Declaration of pgl::Disk
emptyshape.hpp	Public declaration of pgl::EmptyShape
halfplane.hpp	Public declaration of pgl::Halfplane
halfplaneintersection.hpp	Public declaration of pgl::HalfplaneIntersection
line.hpp	Public declaration of pgl::Line
monotonechain.hpp
orientedline.hpp	Public declaration of pgl::OrientedLine
orientedsegment.hpp	Public declaration of pgl::OrientedSegment
point.hpp	Public declaration of pgl::Point and point-label helpers
polygon.hpp
polygonset.hpp
polygonwithholes.hpp
polyline.hpp
ray.hpp	Public declaration of pgl::Ray
rectangle.hpp	Public declaration of pgl::Rectangle
segment.hpp	Public declaration of pgl::Segment
shape.hpp	Runtime variant wrapper over the currently implemented shape types
triangle.hpp	Public declaration of pgl::Triangle
third_party
pdfgen.hpp	Trimmed header-only C++ port of PDFGen for Pangolin canvas export
visualization
canvas.hpp	Lightweight SVG canvas for drawing Pangolin shapes
pgl.hpp	Convenience umbrella header for the PGL library